Method for treating coal



Patented Nov. 22, 1938 PATENT OFFICE METHOD FOR TREATING COAL Oliver M. Urbain and William R'. S temen, Co-

lumbus, Ohio, assignors to Charles H. Lewis,

Harpster, Ohio No Drawing. Application May 10, 1935, Serial No. 20,885

4 Claims.

This invention relates to a process for treating coal. More specifically it is an object and purpose of the invention to provide a process for treating coal to produce a novel product possessing characteristics that render it valuable especially in the treatment of potable and polluted waters.

Specifically, it is the purpose of the invention to produce etherated chlorinated coal by means of a novel efllcient and economical process.

In the preparation of the base material we employ powdered coal such as sub-bituminous, bituminous or anthracite coal, powdered to pass through a 5 mesh to 20 mesh screen. The coal is chlorinated at a temperature varying from room temperature to 125 C. by passing chlorine gas through the mass. Above 125 C. the chlorine compounds decompose, so care should be taken to keep the temperature below this critical point. In this chlorination process, catalysts such as iron, iodine, sulfur or lead may to advantage be employed, though their use is not essential. The temperature of the coal mass rises somewhat during chlorination. Hydrochloric acid gas and I water vapor are copiously given off. Smaller quantities of carbon oxides, hydrocarbons and chlorinated hydrocarbons are given off.

The product of such chlorination contains substantial amounts of chlorine by weight. The percentage of chlorine depends upon the following factors:

1. Fineness of the coal.

2. Nature or kind of coal.

3. Temperature of chlorination.

4. Pressure.

5. Time of chlorination.

The liner the coal, the higher the temperature up to 125 C., the'higher the pressure, and the longer the time of contact to complete chlorination, the higher will be the percentage of chlorine in the finished product. The chlorinated coal is more porous than the original coal, therefore it has a greater surface exposure. The fragility of the chlorinated coal is not appreciably different from that of the original coal when hard coals are employed. When soft coals are employed, the chlorinated product is much. harder than the original coal. The chlorination should be carried out in an apparatus made of materials capable of withstanding the action of hydrochloric acid.

The action of the chlorine on the coal may be expresed by the following factors:

1. Chlorine substitutes for hydrogen in the hydrocarbon part of the so-called coal conglomerate.

2. Chlorine oxidizes certain groupings and opens up the ring structures.

3. Chlorine adds to the unsaturated points in the coal.

4. Chlorine adds to the unsaturalted points made under #2.

5. Chlorine renders soluble the inactive inorganic constituents (coal ash) of the coal, such as iron and its compounds, sulfur and the alkaline earth metal compounds, which, upon removal by washing, open up the coal structure, increasing the active surface of the mass.

6. Chlorine activates the surface of the mass by shifting the adsorbed and absorbed gases.

By etherating the chlorinated coal we have been able to materially increase its activity and effectiveness toward certain groups of organic compounds. The etheration of the chlorinated coal may be eflected in accordance with the following illustrative method.

In accordance with this method of etherating the chlorinated coal, the latter is caused to react, in the manner described below, with any member or any mixture of members of a group of hydroxy compounds or their substituted derivatives.

The group of hydroxy compounds suitable for use in this method, consists of the following:

1. Aliphatic alcohols, such as methyl alcohol, propyl alcohol and allyl alcohol.

2. Cyclic alcohols, such as cyclohexanol and cyclopentenoi.

3. Aromatic alcohols, such as benzyl alcohol, Z-Iurancarbinol and phenethyl alcohol.

The reaction is effected by heating the chlorinated coal with the selected hydroxy compounds. The heating of the mixtures may be either carried out at atmospheric pressure in a return condenser system, or in a closed system at superatmospheric pressures. The former method is more economical while the latter is more rapid, An alkali metal hydroxide such as NaOH, or an alkaline earth metal hydroxide, such as Ca(OH)2, in a concentration varying from 1% to 10% of the weight of the chlorinated coal, should be present. A time period varying from 30 minutes to 6 hours is required for complete reaction. After the reaction is complete theetherated product is recovered and water washed. I

From our research we are of the opinion that the following reactions take place during the above described etheratlon of the chlorinated coal. so

The iollowing symbols have the definitions given:

ROH=hydroxy compound, -:OCi=chlorine atom bound to carbon in the chlorinatedcoal. Thereareapiuralityotsuch groups in a small mass of chlorinated coal.

ll=an alkali hydroxide or an alkaline earth metal hydroxide.

It is to be clearly understood that it is not nec essarytoreplaceallthechlorinewithether The general reaction tor the etheration is as follows:-

ECOR+MCI+H2O etherated coal Specific examples are as follows:

methyl alcohol ECOCH3+N8C1+H2O 7 methyl ethernted coal C-Cl+HOCH:CHs-l'-NaOH benzyl alcohol ECO-CHZ-CCH5+N8-C1+H2O benzyl eihcrated coal Having thus described our invention, what we claim is:

and aromatic alcohols, recovering the etherated 5 product, and washing with water.

2. A process for the preparation of a sorptive etherated coal which comprises reacting chlorinated coal in the presence of an alkali metal hydroxide or an alkaline earth metal hydroxide 10 with a hydroxy compound selected from the group consisting of aliphatic, cyclic, and aromatic alcohols, recovering the etherated product, and washing with water.

3. A process for the preparation of a sorptive etherated coal which comprises heating chlorinated coal with methyl alcohol at a temperature suflicient to effect reaction, recovering the etherated product, and washing with water.

4. A process for the preparation of a sorptive etherated coal which comprises heating chlorinated coal with benzyl alcohol at a. temperature suflicient to effect reaction, recovering the etherated product, and washing with water.

OLIVER M. URBAIN. WILLIAM R. STEMEN. 

